Czatkowiella harae Borsuk-Białynicka & Evans, 2009
Sugerowana cytacja: Tałanda, M. 2014. Czatkowiella harae Borsuk-Białynicka & Evans 2009. Ikonoteka (http://ikonoteka.paleo.pan.pl/xwiki/bin/view/Species/Czatkowiella+harae)
Diagnoza Czatkowiella resembles early archosauromorphs (notably those traditionally grouped as “prolacertiforms”), and differs from lepidosauromorphs in having strongly elongated cervical vertebrae with long low neural spines and slender horizontally placed cervical ribs with an anterior process; it resembles the Late Triassic gliding kuehneosaurs and some archosauriforms, and differs from all described “prolacertiforms”, in having three-headed ribs on some anterior trunk vertebrae, but differs from kuehneosaurs in that these ribs do not attach to the ends of elongated transverse processes; resembles Rhombopholis in having expanded spines on the dorsal vertebrae, but differs in the other vertebral characters noted above; resembles the Late Permian Protorosaurus in combining long cervical vertebrae and slender horizontal cervical ribs with a primitive premaxilla lacking a posterolateral process, but differs in having a biradiate postorbital bone, paired parietals without a median crest, and cervical vertebrae that are proportionally longer in relation to their height, in the possession of some three-headed ribs, in having short dorsal vertebrae with a greater development of a spine table, and in lacking the bifid caudal neural spines that characterize all specimens of the Late Permian genus. In its combination of characters, Czatkowiella is unique and justifies distinct generic status. As reconstructed on the basis of most frequent bones, the skull of Czatkowiella harae was about 40 mm in length (on average), and is thus much shorter than that of Prolacerta broomi B.P.I. 2675 (about 70 mm). However, the presence of very small and very large maxillae demonstrates a range of variability that is consider to be intraspecific. Porównanie Czatkowiella is relatively well known compared to other early diapsids but it has still proved difficult to classify. It shows skull and vertebral characters once thought diagnostic of the long-necked “prolacertiforms” (loss of the parietal foramen, distinct transverse processes on the dorsal vertebrae, double-headed ribs), but most recent (1998-2009) cladistic analyses have failed to support a monophyletic Prolacertiformes. Analysis suggests a relationship between Czatkowiella and the Late Permian Protorosaurus at the base of Archosauromorpha. Czatkowiella is thus to be considered a survivor of the Permian stage of archosauromorph phylogeny. However, this needs to be confirmed with a more detailed analysis at the new material of Protorosaurus. If this hypothesis of relationship is correct, then the similarities found between the cervical vertebrae and ribs of Protorosaurus (sensu stricto) and traditional “prolacertiforms” probably represent the retention of primitive character states, possibly synapomorphic for Archosauromorpha, or, given the cervical morphology of the basal diapsid Petrolacosaurus, for a more inclusive group. Autekologia Terrestrial, probably carnivorous. Występowanie geograficzne Only locus typicus. Zasięg czasowy Only stratum typicum. Materiały muzealne Institute of Paleobiology PAN, Warsaw (ZPAL) Literatura Borsuk-Białynicka, M. and Evans, S.E. 2009. A long-necked archosauromorph from the Early Triassic of Poland. Palaeontologia Polonica 65, 203–234. |
|